On Wed, Aug 30, 2023 at 11:31:35AM +0200, Roberto Sassu wrote:

On Wed, 2023-03-08 at 10:43 -0500, Mimi Zohar wrote:

quoted

Hi Roberto,

On Fri, 2023-03-03 at 19:18 +0100, Roberto Sassu wrote:

quoted

From: Roberto Sassu <roberto.sassu@huawei.com>

In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_removexattr hook.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 fs/xattr.c                    |  1 +
 include/linux/lsm_hook_defs.h |  2 ++
 include/linux/security.h      |  5 +++++
 security/security.c           | 14 ++++++++++++++
 4 files changed, 22 insertions(+)

diff --git a/fs/xattr.c b/fs/xattr.c
index 14a7eb3c8fa..10c959d9fc6 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c

@@ -534,6 +534,7 @@ __vfs_removexattr_locked(struct mnt_idmap *idmap,
 
 	if (!error) {
 		fsnotify_xattr(dentry);
+		security_inode_post_removexattr(dentry, name);
 		evm_inode_post_removexattr(dentry, name);
 	}

Nothing wrong with this, but other places in this function test "if
(error) goto ...".   Perhaps it is time to clean this up.

quoted

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index eedefbcdde3..2ae5224d967 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h

@@ -147,6 +147,8 @@ LSM_HOOK(int, 0, inode_getxattr, struct dentry *dentry, const char *name)
 LSM_HOOK(int, 0, inode_listxattr, struct dentry *dentry)
 LSM_HOOK(int, 0, inode_removexattr, struct mnt_idmap *idmap,
 	 struct dentry *dentry, const char *name)
+LSM_HOOK(void, LSM_RET_VOID, inode_post_removexattr, struct dentry *dentry,
+	 const char *name)

@Christian should the security_inode_removexattr() and
security_inode_post_removexattr() arguments be the same?

Probably this got lost.

Christian, should security_inode_post_removexattr() have the idmap
parameter as well?

Only if you call anything from any implementers of the hook that needs
access to the idmap.